Robotic Arm

Robotic Arm Photo Credit: Biodesign Institute, ASU.

In the "Star Wars" prequels, Anakin Skywalker gets a robotic arm that he'll eventually use as Darth Vader. In this Science Update, you'll hear about a real-life robotic arm that may help stroke victims regain control of their movement.


Robotic physical therapy. I'm Bob Hirshon and this is Science Update.

A robotic arm that can be worn at home may someday help stroke victims regain lost mobility. It's being developed by Arizona State University bioengineer Jiping He and his colleagues, with support from the National Institutes of Health.

The sleeve-like device features four pneumatic muscles, from the shoulder to the wrist, that help the real arm move. As the patient gets stronger over time, the robotic muscles gradually back off.


So that the robot is not like a patient is passively receiving therapy – actually they control the pace of the therapy.

The device is still in the prototype stage, but if it proves successful, it could be a lot cheaper than long-term, one-on-one physical therapy. I'm Bob Hirshon for AAAS, the Science Society.

Making Sense of the Research

Behind all this high-tech research is a simple economic problem: How do you rehabilitate a stroke victim more cheaply? Health care costs have risen quickly in recent years. As people continue to live longer, more and more of them will need treatment for age-related diseases like cancer, Alzheimer's, and stroke. In order to get everyone the treatment they need, medical science needs to figure out how to get more bang for its buck.

Surprisingly, it isn't always the latest technology that costs the most. Human labor remains one of the biggest costs in the health care system. And while scientists can try to build smaller, cheaper, and more efficient medical machines, the cost of paying actual human beings can only increase with time.

So this state-of-the-art robot arm is really a cost-cutting measure. If the patient can use the robot arm to do physical therapy at home, unsupervised, it could save a lot of money in the long run compared to regular home visits from a physical therapist. Of course, a physical therapist would still have to show the patient how to use the arm, and check in periodically, but the number of person-to-person sessions would be far fewer than in a traditional course of physical therapy. As an added bonus, the patient would have round-the-clock access to the arm, so there is potential to do more intense work on a regular basis. Plus, as Dr. He points out, the patient sets the pace of the therapy, moving to the next level of difficulty as soon as he or she is able.

This robot arm looks more like a mechanical sleeve, with external muscles that use compressed air to help the real arm move. The robot arm would help the patient a great deal at first. Gradually, as the patient regains strength, he or she would decrease the power of the muscles until the arm was no longer needed.

One potential downside to technologies like these is the effect it could have on the job market for trained physical therapists. Many jobs that once could be performed only by people are becoming automated, and the medical industry is no exception. So it's important that doctors, as well as patients, can adapt quickly to new technological advances.

Now try and answer these questions:

  1. What is the goal of the robot arm?
  2. How does it differ from a prosthetic arm that replaces a missing limb?
  3. Do you think that replacing one-on-one physical therapy with the robotic arm would be a good thing, overall? Why or why not?
  4. Are there any aspects of medicine that ONLY a human being can perform, no matter what technologies are invented in the future? Explain your answer.

Going Further

For Educators

The Artificial Human, from PBS’ Nova Online, features an activity about artificial body parts for humans.

The Robotic Arm, from How Stuff Works, describes how a robotic arm works and provides animations that show how they move.

Related Resources

Death-Defying Cockroaches
6-8 | Hands-On
Extending Human Ability through Technology
6-8 |
Thought-Controlled Robotics
6-12 | Audio
The Core
6-12 | Audio

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